Chairs having tilting backs



Oct. 23, 1962 R. c. ANGELL ET AL 3,059,970

CHAIRS HAVING TILTING BACKS Fild Feb. 1, 1960 4 sheets-sheet .1

RC BERT C. RNC-IEM., deceased BY JAMES Aussu- Execuron wlw/nm UHLER ATToQNEYS Oct. 23, 1962 R. c. ANGELI. ET AL 3,059,970

CHAIRS HAVING TILTING BAcKs Filed Feb. l. 1960 4 Sheets-Sheet 2 @05am-rC. ANCTELL, dzczaszc BYJAmes BANGELL EXECUTOR 6- WILMER P. UHLER BY9211441", @mic/)s w ATTO 2 N EYS Oct. 23, 1962 R. c. ANGELI. ET AL3,059,970

CHAIRS HAVING TILTING BAcKs Filed Feb. l. 1960 4 Sheets-Sheet 5 JAMESaANGaLL ExEcu'roR BY ,wlLMER RUHLER ATTORNEYS Oct. 23, 1962 R. c. ANGELLET AL 3,059,970

CHAIRS HAVING TILTING BAcKs Filed Feb. l. 1960 4 Sheets-Sheet 4 BY JAMESB.ANGE| L,ExEcu'roR 8-WILMER r. UHLER United States Patent liice 3,59l@Patented Giet. Z3, 1962 gaat 3,059,970 CHAIRS HAVlNG TllZTlNG BACK@Robert C. Angell, deceased, late of Staten island, NPY., by lames B.Angell, executor, Menlo Parli, Salif., and Wilmer l. Uhler, Tottenville,NX., assignors to The S. S. White Dental Manufacturing Company,Philadelphia, Pa., a corporatian of Pennsylvania Filed Feb. l, 1964i,Ser. No. 5,941 14 Claims. (Cl. 297-353) This invention relates toadjustable back structures for chairs, such as those employed bydentists for seating patients, and is particularly concerned with meansfor positioning and holding supports for the back and head of theoccupant.

It is known to have chairs with sliding back rests and head rests, andthe instant matter concerns improvements in supporting, guiding andposition-locking structures.

An object of the invention is the provision of a chair structure havinga back frame, a slidable back rest, a slidable head rest, and a singleguide means for said rests.

Another object is the provision of a chair structure having a backframe, a slidable back rest, frame-carried guiding means for the backrest, and means for compensating at least a part of the weight of theback rest.

Another object is the provision of a chair structure having a backframe, a slidable head rest, frame-carried guiding means for the headrest, and means for compensating a part of the weight of the head rest.

Another object is the provision of a chair structure having a backframe, a slidable back rest, frame-carried guiding means for the backrest, and position-locking means for xing the back rest and including aself-adjusting part cooperative with locking devices acting againstopposed surfaces of said part.

Another object is the provision of a chair structure having a backframe, a slidable back rest, frame-carried guiding means for the backrest, position-locking means for fixing the back rest and including atransversely movable part on the frame and oppositely acting lockingdevices on the back rest cooperative with said part, and manual controlmeans on the back rest for actuating said locking devices.

Another object is the provision of a chair structure having a backframe, a slidable back rest, a slidable head rest, frame-carried guidingdevices for the head rest, position-locking means for fixing the headrest and including a transversely movable part on the back rest andoppositely acting locking devices on the head rest cooperative with saidpart, and manual control means on the head rest for actuating saidlocking devices.

Another object is the provision of a chair structure having a hollowback frame, a closure for the back frame, a slidable head rest,frame-carried guiding means for said rests concealed by said closure,concealed position-locking means for the back rest and effective toprevent upward and downward movements of the back rest, position-lockingmeans for the head rest concealed by said closure and effective toprevent downward movement of said head rest while permitting free upwardmovement thereof, accessible manual control means on the back rest toactuate the position-locking means for the back rest, and accessiblemanual control means on the head rest to actuate the position-lockingmeans for the head rest.

With these and other objects in View, as will appear in the course ofthe following description and claims, an illustrative embodiment of theinvention is shown on the following drawings, in which:

FIG. l is a side elevation of a chair including the instant invention;

FIG. 2 is a rear elevation of the same;

FIG. 3 is a View, on a larger scale, of the rear of the back frame withparts thereon;

FIG. 4 is an upright section, substantially on line 4-4 of FIG. 3;

FlG. 5 is a fragmentary section, substantially on line 5--5 of FIG. 4;

FIG. 6 is a like section, substantially on line 6--6 of FlG. 4;

FIG. 7 is a horizontal section, substantially on line 7-7 of FIG. 3;

FIG. 8 is an explosion view of head rest parts;

PEG. 9 is a horizontal section of certain parts, substantially on line 99 of FIG. 4, at a larger scale.

In these drawings, the illustrated chair is for dentists use; and has abase lll for mounting on a iloor, with a telescoping column il risingtherefrom and having at the top a seat structure i3 with a foot rest l5.A tilting back 16 is pivoted relative to the seat structure foradjustment to and locking in various positions by devices not furthershown but indicated as including a manual control 17 on the back. Thechair is illustrated as having arm rests l8r.

The back i6 of FIGS. l and 2 has a rigid hollow frame Ztl, FIGS. 3 and4, on which the parts according to the invention are mounted. A backcushion 21 is connected by pivots having clamping devices to a slidingmember 22 having transverse projections 23, 24 at its upper and lowerends, these projections having apertures for sliding engagement with theupright guide rods 25 which are fixed at their upper and lower ends inthe frame 20 and are located between the sliding member 22 and the sidewalls 26 of the frame 2G. Upright rods 27, parallel to rods 25, likewiseextend loosely through apertures of the projections 24 and are securedto the frame Ztl at their upper and lower ends. Compensating coilsprings 28 surround the rods 27 and bear against the frame 20 and theend surfaces of pockets formed in the projections 23: these pocketsbeing formed as enlargements around the rods 27 and extending for a partof the vertical dimension of the projections 23 so that the pockets areannular with their end walls providing abutments for the ends of thecorresponding springs. In construction, the blocks 30 may be formed toreceive the rods 25, 27 and the springs 28, and ixedly secured to thelower end of the base frame member: like blocks 31 may be secured to thebase frame at its upper end.

A second sliding member 35 is guided by the rods 25 between theprojections 2.3, 24; and has an upward eX- tension 36 which projectsabove the back lframe 20 and has a pivot mounting 3-7 at its upper endfor the head rest 37a. A rod 38 extends downward from the member 35 at apoint not in vertical alignment with the sliding member 20, and isconnected to a tension coil spring 39 whose other end is connected to anear 46 on a projection 23.

Rubber cushion rings 42 may be provided around the rods 25 at the endsthereof, and between the several sliding structures, to cushion theparts at the ends of travel, and to avoid noise. It is preferred toprovide cushion sleeves 43, eg, of nylon, around the rods 27 to preventnoise as the spring turns move therealong.

A position-locking means for the sliding member 22 which carries theback cushion 21 includes an upright rail 45 which extends along notches46 in the sliding members, and is held by screws 47 at the top andbottom of the frame structure whereby upward and downward movement ofthe rail 45 is prevented. These screws pass through transverse slots 4Sof the rail; and are not tightly engaged therewith, so that lateral ortransverse movement of the rail is permitted at either or both ends. Arear cover member 49 is formed integral with a rearward projection 50.Two horizontally spaced blocks 49a are positioned in abutment with themember 22 and the cover member 49 (FIG. 9), and the assembly ismaintained by screws 49]) which pass through the likewise spaced frontblocks 22a, and the parts 22, 49a and are threaded into the -member 49.The projection 5@ is hollow, and provides a handle for raising themember 22 and the cushion 2l. A manual control button 5l projectsthrough its upper surface; so the position of the cushion can beadjusted by a single hand, with the fingers beneath the projection 50and the thumb upon the button 5l. The button 51 is pivotally mounted ona lever 52 which extends forward between the blocks 49a and has apress-fitted pin 53 which is supported in holes in the front blocks 22a,with a stop screw 53a to limit upward movement of the lever. An uprightthrust rod 5d has its upper end engaged beneath the lever 52 to beforced downward thereby: the rod 54 is guided in a projection 55 on themember 22, FIG. 4, and is threaded near its lower end to receive anadjustable nut sleeve 56, while a reduced lower end is guided in apocket in a vertically slidable locking block 57, FIGS. 4, 5 and 6,which is guided by the rods 5S engaged, FIG. 5, at their upper ends inears of the sliding member 22 and at their lower ends in the plate 59secured to the lower end of the member 22. Compression `springs 60around these rods act to lift the block 57. The block 57 tits looselyaround the rail 45, and has apertured extending wings 6]. at theopposite sides of the rail 45. Laterally outside the wings 6l, themember 22 has upwardly convergent surfaces 62 which may be provided uponreplaceable wear pieces attached to the member 22. Rollers 63 areprovided in the wing apertures, so that they can travel along the sidesof the rail and, upon upward movement relative to the member 22, canwedge between the surfaces 62 and the rail 45 and lock the parts againstdownward movement of the member 22 and its back cushion 2l along theback frame. The block 57 is cut away adjacent the rail 45 illustrativelybelow the wings 61 to provide downwardly convergent surfaces 64. Rollers65 are located between the surfaces 6d and the sides of the rail 45 sothat wedging effects are established when the block 57 is raisedrelative to the sliding member 22. A 'Ugshaped retainer 66, whichextends around the sides of the rail 45, is apertured for the balls 65;and is provided with threaded extensions 67, passing through the plate59, which may be adjusted by nuts 68 to assure that balls 63, 65 arewedgingly engaged upon the upward movement of the block 57.

The upward extension 36 of the second sliding member 35, which carriesthe head rest, has an upright slot between its side walls, for receivinga second upright rail 70 which is secured by screws 71 to the rstsliding member 22 against relative upward and downward movement, butwith permissive lateral movements as with the rail 45. The rear face ofthe extension 36 is in part closed by cover plates 72 secured thereto;these plates 72 having flanges 73 which extend into the slot in theextension 36 and provide guides for the vertical movement of alockcontrolling slide member 74. Near the upper end of extension 36 is aprojection 75 which may be engaged by the fingers of one hand forlifting the second sliding member 35 and the head rest thereon. A thumbbutton 76 extends through an opening in the top of the projection 75,and is pivotally connected to a lever 77 which is pivoted at 78 withinthe extension. The lever 77 rests on the head of a pin 79 which isthreaded in a horizontal flange 80 at the top of the slide member 74. Acompression spring 81 is located around the stem of the pin 79 andinterposed between the ange 80 and a cross piece 82 of the extension 36for urging the slide member 74 and the lever 77 upward. A stop screw S3can be provided in the projection 75 to limit the upward movement of thelever 77.

The sliding member 74 has an opening along its height for the guidingengagement with flanges 73; and has a U-shaped locking block 85 securedat its lower end, this block 85 extending around the sides of the secondrail 70,

with locking rollers 86 carried in apertures of its wing walls. Wedgeblocks 87 are xed in internal notches of the sliding member 35 at thelower end of its vertical slot, and provide upwardly convergent surfaces8S on the member 35 and located in spaced relation from the sides of thesecond rail 70, so that the rollers S6 can become wedged between therail and the surfaces 88 upon downward movement of the member 35relative to the rail or upon upward movement of the block under theaction of spring 8l relative to the member 35.

The hollow of the extension 36 is closed at the upper ront by a closingplate 90 ixed thereto, and having anges 91 extending along the sides ofthe extension. A lower telescoping plate 92 has its lower edge xed tothe upper part of the back frame 2t) for covering the lower part of theextension hollow when the head rest is fully raised; and an intermediateplate 93 telescopes with respect to the plate 92 when the head rest islowered, and has a top ange 94 for engagement by the sliding memberduring relative movements, and bottom portions 95 for engagement withears 96 on the plate 92 to prevent excessive extension.

The illustrative embodiment shows the compactness and externalsmoothness which can be attained. The front of the head rest slide 35,36 at any part above the back frame 2@ comprises the telescoping plateassembly 90, 92, 93, so that the operating parts are protected andconcealed thereby at the rear. The rear of the head rest slide 35, 36has the plates 72 for alike purpose, but with a recess between the anges73 so that this slide 35, 36 can telescope into the back frame withoutinterference by the rear plate 49 thereof and so that the projection 50and button 51 can be mounted close to the top of the frame 20 for easyand convenient access. The guide and spring rods are covered by the rearside plates 95, FIG. 2, so that the sliding member 22 and its parts canmove between them. Therewith the guides, counterbalance springs, lockmembers and rails, and the lock actuators are concealed, and areprotected from contact.

`.When it is desired to adjust the position of the back cushion 2li,e.g. from the full Iline to the dotted line position of FIG. l, thedentist can place the iingers of one hand beneath the projections 50,with the corresponding thumb on the button. Upon pressing the button andlifting the projection, the sliding member 22 moves upward with thecushion 2l thereon, the movement being assisted by the action of thecounterbalance springs 28'. The releasing action is attained from thedownward rocking of .the lever 52 and the downward movement of the rod54 so that the locking member 57 is pressed downward against its springs6l). Therewith the rollers 63 are drawn downward by the wings 6i of themembers 57 and no longer wedge between the convergent surfaces 62 andthe surfaces of the rail 45; and also the member 57 moves relative tothe plate 59 and the retainer 66, so that the rollers 65 are freed ofwedging engagement between the convergent surfaces 62 and the surfacesof the rail 45. The sliding member 22 is then free to move up or down:illustratively it is being lifted by the projection 56, and it will beseen that the pinching engagement of the projection and the button 51 isa natural one and that the travel of the member 22 does not require anychange of this pinching engagement. When the back is to be moveddownward, the depression of the button 511 releases the member, andcontinued pressure on the button 51 forces the member 22 downwardagainst the action `of its springs 28. Upon releasing the button 51, thesprings 60 lift the locking member 57 into position so that its rollers63, 65 reestablish wedging engagement between the respective surfaces62, 64 and the sides of the rail 45. The springs 60 also then actthrough the rod 54 to lift the button 51. The permitted transversemovement of the rail, with the guided movement of the wedging surfaces62, 65 permits automatic compensation between dierential forces beingexerted at the rollers 63,

65 at one side: the rail 45 then yields to the greater force until theforces balance. Thus, no careful adjustment is necessary, andditerential wear is accommodated.

A like operation is performed when .the head rest 37a is to be adjustedvertically with respect to the back-frame and back cushion. In thiscase, the button 76 is depressed `and the head rest structure includingthe sliding member 35 is moved up or down. Therewith, the sliding lock7d is depressed, and the blocl; 35 moves the rollers 86 out of wedgingengagement between the convergent surfaces 88 and the sides of rail 70;and upon release of the button 76, the spring ttl lifts the Elockmembers 74, 85 so that wedging is re-established. Also, the head restmay be raised without operating the button 76, by merely lifting thesliding parts including the members 35', 36, wherewith the rollers 86act as in an over-running clutch. The parts likewise permit automaticcompensation of differential forces atV the rollers 86, in the mannerdescribed for the sliding member 22, and its locking system.

The illustrative practice is not restrictive; and the invention may bepracticed in many ways within lthe scope of the appended claims.

We claim:

l. A chair assembly having `a seat and `a back, said back including aframe having vertical guides, a sliding member movable along saidguides, a back `support on said sliding member, a rail held to the frameagainst relative vertical movement, said sliding member having a lirstsurface thereon convergent upwardly toward the rail, a locking membermovable along Ithe rail relative to the sliding member and means urgingthe same upward, said locking member having a second surface thereonconvergent downwardly toward the rail, a tirst wedging device carried bythe locking member for engagement between said irst surface and therail, a second wedging member carried by the rsliding member forengagement between said second surface and the rail, and manuallyoperable means for pressing said locking member downward relative to thesliding member.

2. A `chair assembly having a seat and a back, said back including aframe having vertical guides, a sliding member movable along saidguides, a back support on said sliding member, a rail held to the yframeagainst relative vertical movement and having permissive lateralmovement, said slider having upwardly convergent rst surfaces locatedwith the rail between them, a locking member movable along the railrelative to the sliding member and means for urging the same upward,said locking member having downwardly convergent second surfaces locatedwith the rail between them, rst locking elements carried by the lockingmember in the spaces between said rst surfaces and the rail, 4secondlocking elements carried by the sliding member in the spaces betweensaid second surfaces and the rail, and manually operable means formoving said locking member downward.

3. A chair assembly having a seat and a back, said back including aframe having laterally spaced vertical guides, a sliding member movablealong said guides, a rail held by said frame against relative verticalmovement and having permissive lateral movement, locking elementseffective to hold said sliding member against relative downward andupward movement along the rail and positioned to act against oppositefaces of the rail, a locking member movable vertically relative to saidframe and said sliding member and cooperative with said lockingelements, spring means to urge `said locking member in one verticaldirection for engaging the locking elements, a manually accessibleelement carried by and movable relative to said sliding member, and aconnection from said manually accessible element to said locking memberfor moving the latter against the action of the spring means lforreleasing said locking elements, said llocking member beingcooperatively connected with said locking elements to lcause said railto move laterally under differing forces by said locking elements4thereon until the locking efforts on said rail are balanced.

4. A chair assembly as in claim 3, in which the sliding member has anoutward projection for engagement for moving the sliding member upward,and in which the manually accessible element is depressibly mounted atthe top of the projection so that ythe thumb of a hand can be employedto depress the manually accessible element for releasing the lockingelements and also produce downward movement of the sliding member, andthe iingers of a hand can be employed to lift the sliding member whenthe thumb thereof has depressed the manually accessible element.

5. A chair assembly having a seat, a back and a head rest, said backincluding a frame having ixedly spaced upper and lower parts andver-tical guides extending between said parts, a sliding back membermovable along said guides between said parts and having verticallyspaced portions engaged with the guides, a sliding head rest membermovable along said guides between said spaced portions of said slidingback member and having second portions engaged with said guides betweensaid back member portions, a back rest carried by the sliding backmember, a head rest carried by said sliding head rest member, means forlocking said sliding back member to the frame, manually operable meanson the sliding back member for releasing said locking means thereof,means for locking said sliding head rest member to said sliding backmember, and manually operable means on the sliding head rest member forreleasing said locking means thereof.

6. A chair assembly as in claim 5, in which each sliding member 'has aprojection by which it may be raised, and in which the manually operablemeans thereof includes a depressible piece located at the top of therespective projection.

7. A chair assembly having a seat, a back and a head rest, said backincluding a yframe having vertical guide rods fixed therein, a rstsliding member having a central portion and upper and lower projectionstherefrom for .guided engagement with the said guide rods, a secondsliding member having a central portion and projections therefrom forguided engagement with said guide rods and located between the upper andlower projections of the iirst sliding member, means for locking theirst and `second sliding members against movement, a back support on theirst member and a head rest on the second member.

8. A chair assembly as in claim 7, including compression spring meansaround a said guide rod for constantly urging said rst member upwardlyalong the guide rods and thereby compensating for the weight of the backsupport, and spring means for urging said second member upwardlyrelative to said irst member.

9. A chair assembly as in claim 7, in which the locking means includes afirst rail secured to the frame against relative vertical movement andhaving permissive lateral movement, a second rail secured to the firstmember against .relative vertical movement and having permissive lateralmovement, devices carried on the first member for engaging oppositesides of the first rail to lock the iirst member to the rst rail,devices on the second member for engaging opposite sides of the secondrail to lock the second member to the first rail, and manually operablemeans for releasing said devices.

l0. A chair assembly as in claim 9, in which the first member and secondmember have upwardly convergent surfaces with the respective railpositioned therebetween, locking members movable relative to the slidingmembers engage and control the said devices, and said manually operablemeans are eective to move said locking members.

11. A chair assembly having a seat, a back and a head rest, said backhaving a frame with vertical guides, a irst sliding member movable alongsaid guides, a back support on said rst member, means `for xing said rstmember against movement relative to said frame, a second sliding membermovable vertically relative to said rst member, a rail secured to therst member, parts on the second member having upwardly convergentsurfaces with the rail between them, a `locking member movable along therail relative to the rail and the second member, locking elementscarried by the locking member for wedging engagement between said railand said surfaces, the rail lbeing mounted for permissive lateralmovement in response to differential pressures by said locking elements,spring means for urging said locking member upwardly, and manuallyoperable means for pressing the locking member downwardly.

12. A chair assembly as in claim 11, in which the `second member has arearward projection for engagement `for lifting the second member, andin which the manually operable means includes `a ydepressible elementlocated at the top of the projection.

13. A chair assembly having a sea-t, a back and a head rest, said backhaving a hol-low frame having xedly spaced upper and lower parts, withvertical guides eX- t'ending between said parts, a rst sliding membermovable on said guides between said parts, a second sliding membermovable on said guides, spring means for urging the rst member upwardrelative to `the frame, spring means -for urging the second memberupward relative t the rst member, a manually operable element near thetopof the first member and means controlled thereby for locking thefirst member to the frame, a manually operable element near the top ofthe second member and means controlled thereby for locking the secondmember to the rst member, and cover plates connected with the frame andextending between said parts for enclosing said guides, spring means andlocking means.

14. A chair assembly as in claim 13, including a first rail secured tothe frame against relative vertical movement and having permissivelateral movement and forming part of the locking means for the rstmember, said means for locking said rst member including devices forengaging opposite sides of said rst rail, a second rail secured lto therst member and forming part of the locking means for the second member,and cover plates for the second member, said cover plates enclosing saidrails.

References Cited in the le of this patent UNITED STATES PATENTS 346,784Stanford Aug. 3, 1886 671,300 Sibley Apr. 2, 1901 1,031,637 Fischer`Tuly 2, 1912 1,814,877 Weber July 14, 1931 2,426,336 Binus Aug. 26,1947 2,905,274 Cook Sept. 22, 1959 2,985,228 Golden May 23, 1961

